This invention relates to combustors and combustion methods, and especially to devices for utilizing fuel and air to heat a load fluid such as water or air.
Combustors utilized to heat a load fluid, such as in utility boilers or for water or space heaters, typically generate a flame which produces hot combustion product gases that flow over tubes containing the load fluid which is to be heated. Where the fuel is burned with air, which contains nitrogen, the high temperature of the flame produces nitrogen oxide which contributes to pollution of the atmosphere. A combustor which could combust a fuel and air at a lower temperature than exists under free flame conditions, and which could produce substantially complete combustion of the fuel, could provide practical heating systems which minimize pollution.